AN INVESTIGATION ON THE USE OF T’BOLI GOLD TAILINGS FROM MINDANAO STATE UNIVERSITY – ILIGAN INSTITUTE OF TECHNOLOGY (MSU-IIT) GOLD PILOT PLANT AS TOTAL REPLACEMENT OF FINE AGGREGATES IN CEMENT MORTAR

Abstract

Gold tailings are waste products produced from the extraction and recovery of gold from its ore. At present, these tailings are in large amounts and are stored in tailings storage facilities, mostly in the form of dams. These gold tailings dams could have serious consequences for the environment and humans if unfortunate events happen. Thus, it is important to utilize these wastes not only to give them value but also to lessen the environmental and human risks they bear. This study investigates the use of gold tailings produced by the Mindanao State University – Iligan Institute of Technology (MSU-IIT) gold pilot plant from the gold ore of T’Boli, South Cotabato, Philippines, as a total replacement of the sand (fine aggregates) component in cement mortar. The chemical compositions of the T’Boli gold tailings were identified using XRF and SEM-EDX analyses. It was found that SiO2, Al2O3, Fe2O3, K2O, and CaO were the major oxide minerals found in the tailings sample. To investigate the effect of the gold tailings on the mechanical property (compressive strength) of the cement mortar, two different formulations of cement and gold tailings (20:80 and 15:85), a controlled formulation with no gold tailings, and two different curing periods (7 and 14 days) were used. The result shows that the formulation of the control sample produces the highest compressive strength of 20.95 MPa at a 14-day curing period. This is followed by the cement mortar in ratios 1:4 and 1:5.7 at a 14-day curing period with a compressive strength of 9.11 MPa and 7.14 MPa, respectively. With these findings, it shows the suitability of T’Boli gold tailings (mining waste) as an alternative to fine aggregates in cement mortar.